1. Field of the Invention
This invention relates to an ultrasonic wave utilizing device which is any one of an ultrasonic wave transmitting, device, an ultrasonic wave receiving device and an ultrasonic wave transmitting/receiving device provided with the ultrasonic wave transmitting device and the ultrasonic wave receiving apparatus, all of which can be used for an obstacle detecting apparatus, a backside monitoring apparatus, a tilt angle measuring apparatus and the like for a vehicle.
2. Description of the Related Art
In the related art, the ultrasonic sensor of an obstacle detecting apparatus for a vehicle, for example, is composed of an ultrasonic vibrator and a processing circuit that applies a driving voltage for making the ultrasonic vibrator to generate an ultrasonic wave, and processes a voltage which is generated by a piezoelectric effect of the ultrasonic vibrator, and the ultrasonic vibrator and the processing circuit are assembled in a case formed of resin. In the case, a vibration preventing member (silicon rubber) is provided around the ultrasonic vibrator, which prevents a direct vibration transmitted from the ultrasonic vibrator to the case. Moreover, a silicon resin is filled into the rear portion of the processing circuit, which prevents moisture. The processing circuit is connected to a controller via a harness and an operation for obstacle detection at a black or corners of the vehicle is performed by this controller. The case has a circular opening face, and the ultrasonic vibrator and the vibration preventing member are inserted into the case from the opening face side and assembled in the case (see, for example, patent document 1: Japanese Unexamined Patent Publication No. 10-332817, page 3 , 3rd column, 45th line–4th column, 12th line, and FIG. 3).
Moreover, the ultrasonic wave generating device of a backside monitoring-apparatus for a vehicle is composed of a main body in which an ultrasonic wave generating element is wrapped by a layer of synthetic resin material and a horn which is opened to the backside of the vehicle. The horn has a conical thin wall which is integrated with the synthetic resin material layer of the main body and the ultrasonic wave generating element is disposed in the backmost portion of an ultrasonic wave emitting hole formed in this conical thin wall. The main body, the horn, and the outer peripheral surface of an annular flange part which is formed integrally with the tip portion of the horn, are covered with a film made of rubber material to prevent leakage of the ultrasonic wave (see, for example, patent document 2: Japanese Examined Patent Publication No. 62-41147, page 2, 3rd column, 6th–13th line and 32nd–35th line, and FIG. 3).
In the obstacle detecting apparatus for a vehicle in the related art, the ultrasonic vibrator and the vibration preventing member are only inserted from its opening surface side. Thus, in an occasion where a vibration face of this device is faced in a horizontal direction when this device is used for detecting obstacles and for monitoring a backside, there is presented no problem. However, in an occasion where its vibration face is faced downward when it is used for measuring a tilt angle, there is some worry that the ultrasonic vibrator and the vibration preventing member may drop from the case.
Further, in the backside monitoring apparatus for a vehicle in the related art, the ultrasonic wave generating element is wrapped by the synthetic resin material layer of the main body. Thus, even if the vibration face is faced downward, ultrasonic wave generating element does not drop from the synthetic resin material layer, but a work of forming the synthetic resin material layer around the ultrasonic wave generating element is required. Moreover, since the main body, the horn, and the outer peripheral surface of the annular flange part are covered with a film, a work of forming the film around the main body, the horn, and the outer peripheral surface of the annular flange, part is also required. Therefore, the backside monitoring apparatus for a vehicle presents a problem that it cannot be easily assembled.